Installation for making bores in a stratum



March 5, 1957 H. B. FEHLM ANN 3 INSTALLATION FOR MAKING BORES IN ASTRATUM Filed Feb. 24, 1954 s Sheets-Sheet 1 INVENTOR lgIiNS BEATFEHLMRNN ATTORNEY March 5, 1957 H. B, FEHLMANN INSTALLATION FOR MAKINGBORES IN A STRATUM Filed Feb. 24, 1954 3 Sheets-Sheet 2 INVENTOR IgQNSBERT FEH MANN ATTORNEY March 5, 1957 H. BFEHLMANN 2,783,972

INSTALLATION FOR MAKING BORES IN A STRATUM Filed Feb. 24, 19543Shets-Sheet 5 Fig.10- 5/ g INVENTOR mus BERT EEHLMRNN ATTO R N EYINSTALLATION FOR MAKING BORES IN A STRATUM Hans Beat Fehlmann, Berne,Switzerland, assiguor to A. G. fur Grundwasserbautem Beme, SwitzerlandApplication February 24, 1954, Serial N 0. 412,343

6 Claims. (Cl. 255-24) This invention relates to an installation formaking bores in a stratum, preferably but not'exclusively in anonliquid-bearing stratum such as for instance clay, limestone and otherstrata of compact formation.

An object of my invention is to provide a borehole tube with a head atits fore-end to be advanced in the stratum and in which the stratummaterial to be removed is carried off through a scavenging pipe insidethe borehole tube, and in which forwardly directed, pressure medium jetsare discharged from the head.

Another object of my invention is to provide an installation for makinghorizontal or inclined bores in a stratum in which the stratum portionlying in front of the head and forming a compact formation is cut outand disintegrated by forwardly directed, pressure medium jets over arange corresponding to at least the larger portion of the largest crosssection of the head and the head is afterwards advanced into the hollowspace obtained by the cutting out and carrying away of the cut away anddisintegrated stratum material.

A further object of my invention is to provide an installation formaking bores in a stratum.

Another object is to provide an installation including a borehole tube,a head connected with the fore end of the borehole tube, a scavengingpipe in the borehole tube, forwardly directed jet nozzles on the head,some of these nozzles being arranged near the largest outercircumference of the head, and means in the scavenging pipe, such as forinstance a backwardly directed jet nozzle or a worm conveyer forcarrying off the disintegrated stratum material through the scavengingpipe.

Other objects and features will be apparent as the following descriptionproceeds, reference being had to the accompanying drawings, illustratingby a non-restrictive way of example an installation in which Fig. 1 is aschematic illustration of the installation,

Fig. 2 is an axial section through the head with the installation partsconnected to it,

Fig. 3 is a top view of the parts shown in Fig. 2,

Fig. 4 is a front view of the head,

Fig. 5 is a section along the line VV of Fig. 2,

Fig. '6 is a section along the line VIVI of Fig. 2,

Fig. 7 is an axial section through a jet nozzle and through the adjacentparts of the head casing,

Figs. 8 and 9 show in a schematic way the directions of the pressurewater jets emerging from the nozzles of the head,

Figs. 10, 11, and 12 illustrate modified constructions of the head.

Referring now to Fig. 1 of the drawings, a shaft 2 stands in the stratum1 which may for instance consist of clay or limestone. Near to the shaftfloor 3 the shaft wall has an opening 4 traversed by a borehole tube 5having at its free end a head 6. The borehole tube 5 which lieshorizontally but may also be inclined with regard to the axis of theshaft, is formulated of several component tubular pieces connected in aknown manner by means of a schematically illustrated coupling 7 withnited States Patent 0 ice the piston rod 8a of a hydraulic press 8. Thehydraulic supply lines (not shown) for the operation of the hydraulicpress 8 are designated by the reference characters 9 and 10. Thisconstruction is well-known. The use of hydraulic presses is, forinstance, described in U. S. Patent No. 2,550,408, where also theaddition and advance of the component pieces of the borehole tube areexplained. The tube 5 is made of component tubular pieces which areshorter than the diameter of the shaft 2, and, after a component piecehas been advanced in the stratum, another component piece is attached inthe shaft 2 to the previously advanced piece, as is wellknown in theart, reference beinghad, for example, to U. S. Patents Nos. 2,550,408and 2,383,496. Inside the borehole tube 5 there are a scavenging pipe11, a pressure pipe 12 for the supply of pressure water to the head 6and a line 13 for the supply of lubricating liquid. The scavening pipe11 discharges into the shaft 2 and the boring sludge flowing through thepipe 11 into the shaft 2 is evacuated to the outside by the pump 14through the pressure line 15 from a suction pipe 14a having a suctionhead 14b. The pressure pipe 12 is connected to a pump 17 by a conduit 16and the tube 13 by a conduit 18 to a pump 19.

Referring to Figs. 2 to 7, the head 6 comprises a cast or welded casing20. Above the scavenging pipe 11 the fore portion of the casing 20 hasinclined intersecting surfaces 21 forming together a ridge approachingthe longitudinal axis of the tube 5 towards their fore end. The fore endof the scavenging pipe 11 is welded or connected in any other way to thehead casing 20, and the pipe 11 is provided with a screw coupling 11a.In front of the scavenging pipe 11 the head casing 20 has an intake portor scavenging opening 22 to the pipe 11. The pressure pipe 12 for thepressure water discharges into a pressure space 23 of the head 6, thisspace being closed at its hind end by a wall 24 traversed by scavengingpipe 11. The conduit 13 for the lubricating liquid discharges into asecond pressure space 25 formed by the walls 24 and 26. A tube 27guiding the borehole tube 5 is fixed to the wall 26 having outletorifices 28 discharging from the pressure space 25 along the outercircumference of the borehole tube 5. The borehole tube 5 is notpositively connected with the head 6 but is only applied to the head bythe drive force imparted to the tube 5 during the advance of the head 6,so that on withdrawing the tube 5 the head 6 stays behind. The tubes 13,12 and 11 are also withdrawn after having been disconnected from head 12in a manner well-known to those skilled in the art, for instance, tubes13 and 12 are pulled from frictional engagement with the walls of theopenings in walls 24 and 26, while pipe 11 may beremoved by unscrewingit from its coupling 11a.

On the roof surfaces 21 of the intermediate portion of the head 6several forwardly directed jet nozzles 29 are provided in such a waythat the forwardly discharged jets meet one another in one point 36(Figs. 8 and 9) in order to increase the blast or jet effect. In thedrawings (Figs. 3 and 4) three nozzles 29 are shown on each surface 21but there may be less or more than three. An other forwardly dischargingjet nozzle 30 is provided at the fore end of the ridge formed by theintersecting surfaces and still another forwardly discharging jet nozzle31 is arranged at the tip of the head 6 beneath the scavenging pipe 11.Three nozzles 32 are mounted on the wall of the scavenging pipe 11,discharging into the pipe 11 in backward direction. There may, however,also be less or more than three nozzles 32. As shown in Fig. 7, all thenozzles 29 and 32 are screwed into eyes 33 of the head casing 20 and ofthe scavenging pipe wall respectively, so that they may be removed andexchanged very easily. The portions 33 may either be cast or weldedeyes.

Referring now to the constructions illustrated in Figs. 10 and 11, aneven plate or shovel 34 is fixed to the lower portion of the head 6 insuch a way that the lower surface of the plate 34 is flush with thelower edge of the head 6. To provide for an appropriate guide of thehead 6 lateral guide Wings 35 (Figure 12) may be provided instead of theplate 34 of Figure 11.

With the aid of the installation as shown and described the operation ofthe apparatus according to the invention may, for example, be carriedout as follows:

Assuming that the head 6 and the borehole tube 5 are alreadyin theposition of Fig. 1, i. e. already partially advanced in the stratum 1.The pump 17 delivers water or another liquid at a pressure of, forinstance, 25 to 100 atmospheres through the conduit 16 and the pressuretube 12 to the pressure space 23 of the head 6. The water pressurechosen in the space 23 is determined by the properties of the stratumlayer or layers to be pierced through and may for instance also amountto 100 atmospheres and even more by using a pump of correspondingdelivery pressure. The pressure Water flows from the pressure space 23through the forwardly discharging jet or blast nozzles 29, 30 and 31 inthe shape of jets with a very high kinetic energy and these jets meetone another at least approximately in a point 36 (Figs. 8 and 9). Thejets have a heavy cutting eiiect and break up the compact formation ofthe stratum portion lying in front of the, head 6 and the cut awaymaterial is carried off by the water of the jets through the scavengingpipe 11 into the shaft 2 where the boring sludge is sucked off by thepump 14. The scavenging effect is considerably increased by jets of highenergy emerging at the same time from the pressure space 23 through thenozzles 32 Wherefrom the jets enter the scavenging pipe 11 in adirection towards the shaft 2. The jets having cut away the stratumportion attainable by them, the borehole tube 5 with the head 6 isadvanced in the stratum by the hydraulic press 8 in order to bring thehead 6 into the hollow space obtained by the previous disintegratingaction of the jets and to advance in this way the forwardly emergingwater jets and the scavenging pipe 11 to the next stratum portion to becut away whereupon the jets cut away this further stratum portion.Advancing the head is repeated until the borehole is completed. Thelubricating liquid (for instance a thixotropic liquid) delivered by thepump 19 and leaving the pressure space 25 of the head 6 through theorifices 28 along the outer wall surface of the tube 5 decreases thefriction between the borehole tube 5 and the stratum 1 surrounding it.The head 6 is preferably designed in such a way that it constitutes asealing together with the surrounding stratum, so that undue escaping ofthe lubricating liquid in the forward direction is prevented. For thisreason, the head must have sufficient length. All the nozzles lie insidethe largest head diameter. The nozzles 29 and 31 lie nearer to the outercircumference of the head 6 than to the center line of the tube 5 andofthe head 6, so that the jets cut out and disintegrate a stratumportion within a range corresponding at least to the larger portion ofthe largest cross section of the head 6. The diameter of the pilot head6 is not appreciably larger than the diameter of theborehole tube 5considering that very long boreholes are often made. Assuming that'thepilot head has already been advanced a considerable distance from theshaft 2, the plastic clay wall of the borehole does not remain stablebut will flow against the tube 5 along a large length and exert a radialpressure and, therefore, produce a considerable frictional forcepredetermined length. The borehole tube 5 is made of component tubularpieces. These pieces are shorter than the diameter of the shaft and,after a component piece has been advanced to the stratum, anothercomponent piece is fixed in the shaft 2 to the previously advancedpiece. However, this feature is also well-known in the art, referencebeing had, for example, to U. S. Patents Nos. 2,126,576, 2,383,496 and2,550,408, and also German Patent 687,049 of 1940.

If a head with a shovel 34 as shown in Figs. 10 and 11 is used supply ofthe cut away material to the scavenging pipe 11 is improved by theshovel 34. At the same time the shovel may serve the head 6 as a guide.

The intake port 22 may be smaller than shown in the drawing in order toprevent large stones from entering and clogging the scavengingpipe 11.

Instead of arranging the jet nozzles 29 to 31 in a manner to obtainconvergence of the jet streams, the axes of the nozzles may be parallelto one another in order to obtain jets parallel to one another.

The pressure of the medium (liquid or gas) to be supplied to the jet orblast nozzles 29 to 31 can be chosen in such a way that even hard rockor wood can be decomposed by the jets.

In certain cases compressed gas such as, for instance, compressed aircan be used instead of pressure water, especially when the stratum layerto be traversed is not completely dry.

In order to increase the cutting effect of the jets granular materialsuch as, for instance, sand or quartz can in certain cases be added tothe liquid or gas jets discharged by the nozzles 29 to 31.

Instead of advancing the borehole from a shaft, it may also be advanceddirectly from the soil surface in any direction desired.

The apparatus according to the invention is especially well suited formaking boreholes and siphons under rivers, buildings and otherconstructions etc., but is not limited thereto.

Many changes may be made in the described method and installation whileretaining its features and operating principles.

I claim:

1. In an installation for making bores in a stratum, a borehole tube, ahollow pilot head in abutting relationship with the fore end of theborehole tube and adapted to be driven thereby, the pilot head havingfore and intermediate portions with a scavenging opening in the foreportion, the pilot head including a body member, a pair of intersectingsurfaces extending from the intermediate portion of the head towards thefore end thereof and inclined downwardly at an angle to the longitudinalaxis of the borehole tube, the intersection thereof forming a ridge alsodirected downwardly towards the longitudinal axis .of the borehole tubeand tapering towards the fore end of the head, means forming a lubricantchamber within the pilot head, means forming an outlet 'for thelubricant chamber adjacent the fore end of the borehole tube, the bodymember of the pilot head providing a'high pressure fluid chamber, ascavenging conduit extending through the borehole tube and said chambersand terminating at said scavenging opening, a high pressure fluid supplyconduit extending through the borehole tube and discharging intothe highpressure fluid chamber, a lubricant supply conduit extending through theborehole tube and discharging into the lubricant chamber, at least oneforwardly directed jet nozzle for the high pressure fluid chamberextending through one of the intersecting surfaces and positionedtowards the intermediate portion, at least another forwardly directedjet nozzle for the high pressure chamber extending through one of theintersecting surfaces and positioned at the fore end .of the ridgeadjacent the scavenging opening, at least still anotherforwardlydirected jet nozzle for the high pressure chamber andpositioned at the fore end of the pilot head on the opposite side of thescavenging opening with respect to the second-mentioned jet nozzle, anda back- Wardly directed jet nozzle for the high pressure chamberextending into the scavenging conduit.

2. In an installation for making bores in a stratum, a borehole tube, ahollow pilot head in abutting relationship With the fore end of theborehole tube and adapted to be driven thereby, the pilot head havingfore and intermediate portions with a scavenging opening in the foreportion, the pilot head including a body member, a pair of intersectingsurfaces extending from the intermediate portion of the head towards thefore end thereof and inclined downwardly at an angle to the longitudinalaxis of the borehole tube, the intersection thereof forming a ridge alsodirected downwardly towards the longitudinal axis of the borehole tubeand tapering towards the fore end of the head, the body member of thepilot head providing a high pressure fluid chamber, a scavenging conduitextending through the borehole tube and said chamber and terminating atsaid scavenging opening, a high pressure fluid supply conduit extendingthrough the borehole tube and discharging into the high pressure fluidchamber, at least one forwardly directed jet nozzle for the highpressure fluid chamber extending through one of the pair of intersectingsurfaces and positioned towards the intermediate portion, at leastanother forwardly directed jet nozzle for the high pressure chamberextending through one of the pair of intersecting surfaces andpositioned at the fore end of the ridge adjacent the scavenging opening,at least still another forwardly directed jet nozzle for the highpressure chamber and positioned at the fore end of the pilot head on theopposite side of the scavenging opening with respect to thesecond-mentioned jet nozzle, and a backwardly directed jet nozzle forthe high pressure chamber extending into the scavenging conduit.

3. In an installation for making bores in a stratum, a borehole tube, ahollow pilot head in abutting relationship with the fore end of theborehole tube and adapted to be driven thereby, the pilot head havingfore and intermediate portions with a scavenging opening in the foreportion, the pilot head including a body member, a pair of intersectingsurfaces extending from the intermediate portion of the head towards thefore end thereof and inclined downwardly at an angle to the longitudinalaxis of the borehole tube, the intersection thereof forming a ridge alsodirected downwardly towards the longitudinal axis of the borehole tube,and tapering towards the fore end of the head, the body member of thepilot head forming a high pressure fluid chamber, a scavenging conduitextending through the borehole tube and said chamber and terminating atsaid scavenging opening, a high pressure fluid supply conduit extendingthrough the borehole tube and discharging into the high pressure fluidchamber, at least one forwardly directed jet nozzle for the highpressure fluid chamber extending through one of the intersectingsurfaces and positioned towards the intermediate portion, at leastanother forwardly directed jet nozzle for the high pressure chamberextending through one of the intersecting surfaces and positioned at thefore end of the ridge adjacent the scavenging opening, and at leaststill another forwardly directed jet nozzle for the high pressurechamber and positioned at the fore end of the pilot head on the oppositeside of the scavenging opening with respect to the second-mentioned jetnozzle.

4. In an installation for making bores in a stratum, a borehole tube, ahollow pilot head having a fore scavenging opening disposed at the foreend of said borehole tube and adapted to be driven thereby, the pilothead having a portion tapering towards the scavenging opening, meansforming a lubricant chamber within said pilot head discharging outwardlyof said borehole tube, and means forming a pressure fluid chamber withinsaid pilot head, a scavenging conduit located within said borehole tubeand said chambers and in fluid communication with said scavengingopening, a pressure fluid supply conduit located within said boreholetube and discharging into said pressure fluid chamber, a lubricantsupply conduit located within said borehole tube and discharging intosaid lubricant chamber, at least one forwardly directed jet nozzle influid communication with said high pressure fluid chamber and mounted onsaid tapered portion of the pilot head, and a backwardly directed jetnozzle on said scavenging conduit in fluid communication with saidpressure fluid chamber and discharging into said scavenging conduit.

5. In an installation for making bores in a stratum, a borehole tube, apilot head having a scavenging opening disposed at the fore end thereofand adapted to be driven by the borehole tube, means forming a pressurefluid chamber within said pilot head, a scavenging conduit' locatedwithin and running longitudinally of said borehole tube and said chamberand in fluid communication with said scavenging opening, a pressurefluid supply conduit located within and running longitudinally of saidborehole tube by the side of said scavenging conduit and discharginginto said chamber, and a forwardly directed jet nozzle in fluidcommunication with said pressure fluid chamber and positioned on saidpilot head.

6. In an installation for making bores in a stratum, a borehole tube, apilot head having a scavenging opening disposed at the fore end thereofand adapted to be driven by the borehole tube, means forming a pressurefluid chamber within said pilot head, a scavenging conduit locatedwithin and running longitudinally of said borehole tube and said chamberand in fluid communication with said scavenging opening, a pressurefluid supply conduit located within and running longitudinally of saidborehole tube by the side of said scavenging conduit and discharginginto said chamber, a forwardly directed jet nozzle in fluidcommunication with said pressure fluid chamber and positioned on saidpilot head, and a guide plate fixed to and extending beyond said pilothead.

References Cited in the file of this patent UNITED STATES PATENTS281,415 Stone July 17, 1883 973,752 Cahn et a1. Oct. 25, 1910 1,512,140Schaub Oct. 21, 1924 1,639,731 Humiston Aug. 23, 1927 1,853,379 RotinoffApr. 12, 1932 2,122,099 Jeffrey June 28, 1938 2,325,565 Williams July27, 1943 2,383,496 Nebolsine Aug. 28, 1945 2,678,203 Hufi May 11, 1954

